Cooling troughs for open liquid-coolers of power modules generally have a supporting surface for power modules which are to be attached thereto. This supporting surface is generally arranged so as to run around the periphery of the cooling surface and has a device for holding sealing elements and a device for holding fastening elements (for example fastening screws). The baseplates of power modules are typically then screwed to the surrounding supporting surface using seals.
According to a patent application US20140204533, as shown in FIG. 1, the surrounding supporting surface 11a of the cooling trough 11 is typically configured essentially on a plane parallel to the baseplate 12. A seal 13 is compressed between the cooling trough 11 and the baseplate 12 to seal the opening of the cooling trough 11.
As shown in FIG. 2, according to the patent application US20140204533, the supporting surface 21a of the cooling trough 21 can also be selectably configured with an inwardly directed negative gradient in order to provide the baseplate 22 with a desired pretension against the seal 23 and to reduce any risk of fracturing for the ceramic substrates which are arranged on the baseplate 22.
The description given in US20140204533 of the general background technology, and of the particular problem to be solved, is also valid the current invention.
Depending on the design of the power modules to be cooled, the supporting surface must be constructed very precisely. A supporting surface which is constructed essentially parallel to the baseplate can, in the case of comparatively thin baseplates, cause a bending torque to be applied to the baseplates by the seal and the screws, which brings about curvature of the baseplates, which in an extreme case results in fracturing of the ceramics attached thereto.
An inwardly directed negative gradient has to be produced at very high cost by means of suitable processing steps and can be controlled, in terms of its very small angle of inclination, only with great difficulty.